FastAPI Todo Application (Full Stack with Authentication)

A full-stack Todo application built using FastAPI, PostgreSQL (Supabase), and Jinja2 templates, featuring authentication, CRUD operations, and testing.

This project demonstrates real-world backend engineering concepts including:

• JWT Authentication
• Dependency Injection
• Database Integration (Supabase PostgreSQL)
• Role-Based Access Control (User & Admin)
• Modular FastAPI Architecture
• Testing with Pytest

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🚀 Features

• User Registration & Login
• Secure JWT-based Authentication
• Cookie-based Session Handling
• Full CRUD Operations (Todos)
• Protected Routes
• Supabase PostgreSQL Integration
• Modular Code Structure
• Unit & Integration Testing

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🛠️ Tech Stack

• Backend: FastAPI
• Database: PostgreSQL (Supabase)
• ORM: SQLAlchemy
• Authentication: JWT (PyJWT)
• Frontend: Jinja2 Templates (Server-Side Rendering)
• Testing: Pytest
• Server: Uvicorn
• Containerization: Docker

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📸 Application Screenshots

🔐 Login Page

📝 Register Page

📋 Todo Dashboard

✏️ Edit Todo

🗄️ Database Schema

📊 Tables View

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📂 Project Structure

TodoApp/
│
├── Todoapp/
│ ├── routers/
│ │ ├── auth.py
│ │ ├── todos.py
│ │ ├── users.py
│ │ └── admin.py
│ │
│ ├── templates/
│ ├── static/
│ ├── database.py
│ ├── models.py
│ └── main.py
│
├── test/
├── .env
├── requirements.txt
├── Dockerfile
├── docker-compose.yml
└── README.md

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Authentication Flow (JWT)

User Login
↓
FastAPI /token
↓
authenticate_user()
↓
create_access_token()
↓
JWT Token Generated
↓
Stored in Browser Cookie
↓
Sent with every request
↓
get_current_user()
↓
User Authenticated ✅

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Cookie Authentication Flow

Login success
   ↓
Token stored in cookie
   ↓
Browser sends request
   ↓
Cookie auto-attached
   ↓
Backend verifies user
   ↓
Access granted ✅

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Setup Instructions

1️⃣ Clone Repository

git clone <your-repo-url>
cd todoapp

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2️⃣ Create Virtual Environment
python -m venv venv
venv\Scripts\activate


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3️⃣ Install Dependencies
pip install -r requirements.txt


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4️⃣ Setup Environment Variables

Create .env file:

DATABASE_URL=postgresql://username:password@host:port/database
SECRET_KEY=your_secret_key


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5️⃣ Run Application
uvicorn Todoapp.main:app --reload

App runs on:

http://127.0.0.1:8000

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Key Learnings

• FastAPI Dependency Injection
• JWT Authentication
• PostgreSQL + Supabase Integration
• Clean Backend Architecture
• Testing with Pytest
• Cookie-based auth handling

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Future Improvements

• React Frontend Integration
• Role-based Access Control (RBAC)
• Pagination & Filtering
• Deployment (AWS / Azure)

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📌 Author

Namit Jain Machine Learning & AI Engineer

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